For historical reasons, the VRI photometry has produced several systems
which have quite similar, but the V-R and R-I indices are not exactly
in the same standard system. Therefore a datatype has been attributed to
each realisation of the VRI fileter combination.
The datatype ric refers to the RI photoelectric photometry in the
system of Kron. In some observation sets, only the R and I colours
have been observed.
|R-I||:||R-I colour index|
List of clusters
Query the references
Last Update: 19 May 1998